Q: What does a grand jury do?

A: Specifically, grand juries were used to bring the everyday person's perspective into two aspects of government: investigating crime and/or the community conditions and bringing charges against people who may have committed crimes.

Bringing charges

In the federal system and in all but two of the states, grand juries are used to bring charges against persons who are believed to have committed crimes. In the federal system and in some states, they have to be used to bring charges for felonies, which are the more serious crimes that normally carry a prison term for those who are convicted. In Texas, they can be used to bring charges for felonies (or for other crimes), but don't have to be used. If a prosecutor doesn't have to use a grand jury, he or she can bring charges on their own, using what is called an "information" as the charging document. When a grand jury brings criminal charges, the charges are contained in a charging document that is called an "indictment."

If a prosecutor wants a grand jury to charge someone, the prosecutor reserves time with the grand jury and then presents evidence to them. In presenting the evidence, the prosecutor is trying to persuade the grand jurors that the people he or she wants to charge have committed certain crimes. The evidence can be almost anything--testimony from witnesses (including police officers or federal agents), documents, video recordings, tape recordings, the results of scientific tests (like DNA tests), photographs, etc.

The grand jurors listen to the evidence and decide if it establishes probable cause to believe the person the prosecutor wants to charge has committed the crime(s) the prosecutor claims.

After they hear all the prosecutor's evidence, the jurors vote on a set of proposed charges--known as an "indictment"--which the prosecutor has drafted and gives to the grand jurors. If the grand jurors decide the evidence creates probable cause to believe the persons named in an indictment committed the crimes it charges them with, they vote to "return" the indictment, i.e., to charge the person with those crimes. Voting to return charges is usually known as "returning a true bill." If a grand jury votes to return a true bill, the indictment is valid and it initiates a criminal case against the people named as defendants in the indictment. A simple majority of the grand jurors must vote for an indictment in order to return a true bill.

If a majority of the grand jurors don't think the prosecutor's evidence creates probable cause, they will vote not to return the indictment. When a majority of grand jurors vote not to return an indictment, this is known alternatively as "returning a bill of ignoramus" or "returning a no bill." If the grand jurors vote not to return an indictment, the indictment is not valid and no criminal case results.

But even if a grand jury votes not to indict, that isn't the end of things. A grand jury's vote not to return an indictment is not a final judgment that triggers the constitutional protection against "double jeopardy." To be protected against double jeopardy, a person has to have been "put into jeopardy" and then the proceeding in which "jeopardy attached" had to end without that person's being convicted. The basic rule of thumb is that "jeopardy attaches" when the first witness is sworn in a bench trial (that is, a trial to the court, where there is no jury) or when the jury is sworn in if the case is to be tried by a jury. This means, for example, that if a jury has been sworn in and heard the evidence in a criminal case and they vote to acquit the defendant, he or she cannot be re-tried on those charges. That is precisely what happened to O.J. Simpson: Because the jury in the criminal case acquitted him, he cannot be re-tried on any charges arising out of the death's of Nicole Brown Simpson or Ronald Goldman. (The civil trial was not barred by double jeopardy because the double jeopardy provision only protects you from being repeatedly tried on the same criminal charges.)

Investigating

Grand juries also investigate, either as part of bringing criminal charges or as a purely separate function.

Many states have "regular" (indicting) grand juries. But a number of states also have grand juries that investigate organized crime, especially organized drug crime. And some states let grand juries investigate any kind of crime--organized or otherwise. A few states follow the old, common law practice and let grand juries initiate their own investigations based on what the grand jurors know about what is going on in their community. At common law, grand juries could bring criminal charges in a special document--which was known as a "presentment"--when they acted on their own. If they returned charges brought to them by a prosecutor, those charges were contained in an indictment. If the grand jury acted without the prosecutor, they brought charges in a presentment. Some states still let grand juries do this. Both the presentment and the indictment have the same legal effect--both initiate a criminal case.